In welding cast-steel it should be kept from the air during the heating and should be heated as quickly as possible. It should not be made too hot or it is liable to either burn or break in pieces while being hammered.

Coke, not coal, should be used for the fire, as the latter contains sulphur, which would give the surface of the steel a sulphide or iron coating. The following is the flux to use:

1/4 pound Washing Potash, 1/4 pound Borax, and a small quantity of white glass, powdered. These ingredients being mixed together, and, when cold, powdered. This flux will accomplish the dissolution of oxide formations. Before the steel is placed in the fire apply some to protect the surface of the work from oxide.

(2) A welding compound that is excellent for cast-steel is composed of:

3 to 5 parts Carbonate of Soda,

15 5-10 to 26 7-10 parts Ferro-cyanide of Potash. 35 parts Common Salt,

7 6-10 parts Resin,

41 5-10 parts Boric Acid.